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Effect of Processing Conditions on the Flash Onset Temperature in Hydroxyapatite
When heat and electric field are applied to the sample, sintering takes place within a short time of a few seconds by the flash phenomenon that occurs. In what condition flash does occur is a main issue for the flash sintering technique. In this study, the effect of processing conditions such as sin...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8469700/ https://www.ncbi.nlm.nih.gov/pubmed/34576453 http://dx.doi.org/10.3390/ma14185229 |
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author | Hwang, Changhun Yun, Jondo |
author_facet | Hwang, Changhun Yun, Jondo |
author_sort | Hwang, Changhun |
collection | PubMed |
description | When heat and electric field are applied to the sample, sintering takes place within a short time of a few seconds by the flash phenomenon that occurs. In what condition flash does occur is a main issue for the flash sintering technique. In this study, the effect of processing conditions such as sintering atmosphere, sample size, density and grain size on the flash onset of hydroxyapatite was investigated. In a vacuum atmosphere, a flash occurred at a lower temperature by 50–100 °C than in air. The smaller the thickness of the sample, the higher the flash onset temperature due to the larger specific surface area. Flash was also observed in samples which were presintered, having a density of 86–100% and a grain size of 0.2–0.9 μm. When the density and grain size of the sample were higher and larger, the flash onset temperature was higher. It was because the diffusion and conduction path through the grain boundary and the inner surface of the pores with high defect concentration are blocked with an increase of density or grain size. When an electric field was applied during flash sintering, a color change of the sample was observed and the reason was discussed. |
format | Online Article Text |
id | pubmed-8469700 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-84697002021-09-27 Effect of Processing Conditions on the Flash Onset Temperature in Hydroxyapatite Hwang, Changhun Yun, Jondo Materials (Basel) Article When heat and electric field are applied to the sample, sintering takes place within a short time of a few seconds by the flash phenomenon that occurs. In what condition flash does occur is a main issue for the flash sintering technique. In this study, the effect of processing conditions such as sintering atmosphere, sample size, density and grain size on the flash onset of hydroxyapatite was investigated. In a vacuum atmosphere, a flash occurred at a lower temperature by 50–100 °C than in air. The smaller the thickness of the sample, the higher the flash onset temperature due to the larger specific surface area. Flash was also observed in samples which were presintered, having a density of 86–100% and a grain size of 0.2–0.9 μm. When the density and grain size of the sample were higher and larger, the flash onset temperature was higher. It was because the diffusion and conduction path through the grain boundary and the inner surface of the pores with high defect concentration are blocked with an increase of density or grain size. When an electric field was applied during flash sintering, a color change of the sample was observed and the reason was discussed. MDPI 2021-09-11 /pmc/articles/PMC8469700/ /pubmed/34576453 http://dx.doi.org/10.3390/ma14185229 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Hwang, Changhun Yun, Jondo Effect of Processing Conditions on the Flash Onset Temperature in Hydroxyapatite |
title | Effect of Processing Conditions on the Flash Onset Temperature in Hydroxyapatite |
title_full | Effect of Processing Conditions on the Flash Onset Temperature in Hydroxyapatite |
title_fullStr | Effect of Processing Conditions on the Flash Onset Temperature in Hydroxyapatite |
title_full_unstemmed | Effect of Processing Conditions on the Flash Onset Temperature in Hydroxyapatite |
title_short | Effect of Processing Conditions on the Flash Onset Temperature in Hydroxyapatite |
title_sort | effect of processing conditions on the flash onset temperature in hydroxyapatite |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8469700/ https://www.ncbi.nlm.nih.gov/pubmed/34576453 http://dx.doi.org/10.3390/ma14185229 |
work_keys_str_mv | AT hwangchanghun effectofprocessingconditionsontheflashonsettemperatureinhydroxyapatite AT yunjondo effectofprocessingconditionsontheflashonsettemperatureinhydroxyapatite |